Flashlights in the cold: the cell decides, not the light

If a light has to work in genuine cold, buy one that takes lithium primaries - and our pick is the Streamlight PolyTac, which runs on two CR123A cells Energizer rates for operation from -40 C to 60 C. The flashlight is almost never the problem in winter. The cell is, and the difference between the chemistries is published: a lithium primary is rated 22 degrees Celsius colder at the bottom of its range than an alkaline, and a sealed lithium-ion pack brings a hazard neither of them has.

We have not tested anything in a freezer. We own none of these lights, we have no cold chamber, and nothing on this page is a measurement of ours. What follows is what three cell datasheets and five product pages state, plus arithmetic - see our methodology.

What the cell makers publish

Flashlight manufacturers publish lumens and hours. Almost none of them publishes an operating temperature, so the figures that answer this question come from the companies that make the batteries. All three sheets below are Energizer's own, read on October 17, 2026.

That alkaline row is the practical finding of this page. Zero degrees Fahrenheit is not an unusual winter night in a large part of the United States, and it is the published floor of the most common cell format in the world. Below it, Energizer is not telling you the cell fails - it is telling you the cell is outside the range the specification covers.

Why cold costs you output as well as hours

A cell in the cold has higher internal resistance, and internal resistance is what sets how much current a battery can deliver before its voltage sags. A flashlight driver responds to sag by reducing output or stepping down a mode - so a cold light is often a dimmer light before it is a shorter-lived one.

Energizer prints an internal resistance figure for both chemistries, measured at 21 C: 120 to 240 milliohms for the lithium AA, and 150 to 300 for the alkaline. Those are room-temperature numbers and we are not going to extrapolate them down the scale. They do establish the starting order, which is the same order as the temperature ratings.

Energizer also publishes a maximum continuous discharge for each: 2.5 amps for the lithium AA and 1.5 amps for the lithium AAA. On a 1,000-lumen AA light that figure matters more than capacity does, and it is another reason the lithium cell is the one to put in a light you are asking to work hard in bad conditions. How runtime is computed sets out the rest of the arithmetic.

The one thing never to do

That hazard is specific to charging rather than to using a lithium-ion light in the cold, and it is the strongest argument against a sealed rechargeable as a winter light: the light you most want to top up in a cold vehicle is the light you must not.

What this means for the three kinds of light you can buy

The fourth row is the one worth noticing, because it is rare and because Petzl publishes enough to prove it. A hybrid lamp runs on its rechargeable pack and accepts three AAA cells when the pack dies - and if those AAA cells are lithium primaries, the lamp's cold floor becomes the cell's -40 C rather than the pack's. That arrangement is the single best answer to winter in this whole category, and almost nobody markets it that way.

What we would buy for the cold

[Streamlight PolyTac](/tactical-flashlights/streamlight-polytac-review) - best overall cold-weather light. Two CR123A lithium primaries, included, on a light that publishes 600 lm / 11,500 cd / 214 m with 2.75 h, 5.5 h and 34 h across three modes, plus IPX7 and a tested 3 m impact rating at 119 g. The candela and the distance reconcile in every mode. Honest downsides: no low mode under 35 lumens, no magnet, and CR123A cells cost more than AA.

[Petzl Actik Core](/headlamps/petzl-actik-core-review) - best for working in the cold. Cold work is hands-busy work, which makes it headlamp work. Petzl publishes 625 lm, 115 m, a 4.5 Wh pack and a full per-mode table for both power sources, so you can carry the pack and three lithium AAA cells and know what each gives you. 88 g. Honest downsides: IPX4 is rain rather than immersion, there is no red mode, and the 625-lumen setting runs two published hours.

[Streamlight ProTac HL-X](/tactical-flashlights/streamlight-protac-hl-x-review) - best if you need reach as well. 1,300 lm, a published 35,000 cd and 374 m, IP68, a tested 2 m impact rating, and - the reason it is here - a complete published runtime table on CR123A primaries as well as on its own pack: 1 h 15 min, 3 h and 20 h. Honest downsides: it costs more than the PolyTac, Streamlight does not publish its pack's capacity, and the programmable interface takes learning.

[Maglite Mini LED 2-Cell AA](/edc-flashlights/mini-maglite-led-review) - best cheap answer. Two AA cells, so a set of lithium AA primaries turns it into a -40 C light for a few dollars, and Maglite publishes 127 lm, 6,093 cd, 156 m, 11 h on high and 25 h on low. At 48 candela per lumen it reaches further than anything else here. Honest downsides: 127 lumens is dim by modern standards, IPX4, and 118 g of aluminum is cold to hold.

[Acebeam Pokelit AA](/edc-flashlights/acebeam-pokelit-aa-review) - best for seeing color in the cold. CRI 90-plus, IP68, 1,849 cd, 86 m, three published runtimes and 54.6 g, on a cell format that has a lithium primary option. One caveat that matters on this page: the cell in the box is a 14500 lithium-ion rechargeable, which is the chemistry with the charging restriction. Run it on a lithium AA primary for winter and accept that Acebeam publishes no separate figures for that cell.

What we would not buy for the cold

A sealed rechargeable with no cell fallback. Several lights we rate highly elsewhere fall here, including every lamp whose battery is glued in. The objection is not that they stop working when cold - it is that the only way to refill them is the one operation you must not perform on a cold cell.

Anything whose maker publishes no runtime. Cold reduces what a cell delivers, and you cannot reason about a reduction to a number that was never stated. Half of the brightest tactical flashlights publish no runtime at any level, which makes them impossible to plan a cold night around.

A light you have to hold. At -10 C you are wearing gloves, and a 118 g aluminum tube is both slippery and a heat sink against your palm. This is the practical argument for a headlamp or a light with a clip or a magnet, and it has nothing to do with specifications - see flashlight versus headlamp.

Four habits that do more than any purchase

1. Carry the spare cells inside your jacket, not in the light. A warm cell put into a cold light performs like a warm cell for a while.
2. Let a light warm up before charging it. The hazard is charging cold, not being cold.
3. Run a lower mode. Less current means less voltage sag, and a 100-lumen setting that lasts is worth more than a 1,000-lumen setting that steps down.
4. Take alkalines out of lights you store. They leak as they age and the leak usually destroys the light - the one failure mode that is worse than a flat battery.

And the honest limit of this page: we can tell you the published operating range of a cell and the published runtime of a light. We cannot tell you how either behaves at a particular temperature, because nobody publishes that as a number and we are not going to produce one. If that is the figure you need, the car emergency kit page applies the same chemistry to the place a household actually stores batteries badly.